Incredibly important and correct point, but I'd add one thing. Fan base doesn't change for any school because you expand the conference. But I think everyone believes that it's possible that you can increase national interest by moving a regional conference into other reasons. Plus, monopolization increases profitability, and thus preventing someone else from having a monopoly can increase everyone else's profitability.
I may be about to out kick my coverage, but I don't believe the network/expansion candidate relationship and related analysis is based on increasing the fan bases of existing conference partners. It's based on the expansion candidates ability to add tangible value in the form of
end-user connections to the network; and, secondarily, other sources such as bowl appearances and NCAA credits. Can/does Uconn generate enough interest within it's well-to-do, number-twenty sized DMA, to generate end-user numbers that make it attractive to existing conference members. Will Uconn increase revenue opportunities or dilute the value of a conference? Relevant questions.
Next, it is possible for a conference to increase or improve national interest if the candidate chosen, in a new region, has a significant national presence of its own.
Because of conversations about ESPN and chord cutting, and its possible effects, "
end-user connections to the network" needs discussion.
There are two truths:
1) no content provider (conference) is going to give the stuff away, regardless of technology/transport;
2) while the end-user interface(s) will constantly change, end-users,
especially sports fans, will want and be willing to pay for content.
So, it doesn't matter if the transport providers are using Dixie Cups-and-string, high frequency GHz transmission speed wireless or various protocols available to copper and/or fiber. If content providers are going to be paid, and transport providers are going to pay for content, then end-users are going to pay for transport, regardless of method, including streaming services. Kind of brings us back to the necessity of expansion candidates having comparatively large, well-to-do DMA's. In any event, the cable box count might drop, but impact on end-users paying for content will be negligible.
Oh, and end-users that opt for seemingly less expensive services should purchase a reverse chastity belt. There's a man with a barbed, un-lubricated pole on his way to your home.